The present invention relates to a control system for a plant, and more particularly to a control system that identifies model parameters of a controlled object model which is obtained by modeling the plant, and includes a controller for controlling the plant using the identified model parameters.
There has been known a control system that identifies model parameters of a controlled object model which is obtained by modeling a plant which is a controlled object, and includes a controller for controlling the plant using the identified model parameters (Japanese Patent Laid-open No. 2000-297679, for example). This control system includes a model parameter identifier for identifying the model parameters on a real-time basis, and controls the plant using the identified model parameters.
The model parameter identifier calculates an identifying error that is a difference between a predicted output of the plant, which is calculated using the identified model parameters and an actual output of the plant. Further, the model parameter identifier corrects the model parameters according to the identifying error.
However, when the actual plan output abruptly changes, an excessive identifying error is generated to make the correction amounts of the model parameters become large. As a result, the plant output sometimes overshoots the target value.